Stinson parking lot collapses in storm

David Briggs
Floodwaters last Friday swept out a swath of asphalt at the north end of the Stinson Beach parking lot, which is closed indefinitely.

By

Anna Guth

04/12/2018

The northern part of the Stinson Beach parking lot is closed indefinitely after last weekend’s subtropical storm flooded Easkoot Creek and carved out a roughly 150-square-foot chunk of pavement fronting the beach.

The storm dropped the second largest amount of rain within a 24-hour period in four decades, at just over four inches, and 6.65 in total, at Point Blue’s rain gauge in Bolinas. Flood waters rushed over the beach parking lot to the Parkside Café, which borders the lot.

The restaurant temporarily closed its marketplace and snack bar due to water damage, though both are now open. The Parkside switched to paper plates and plastic utensils to lessen the impact to its septic system.

The beach parking lot has suffered lesser damages from storms in recent years. Historically, Easkoot Creek forked from its usual pathway that runs closer to Highway 1 and drained where the parking lot now lies and into the ocean during large storms, said John Washington, a former president of the county’s Flood Advisory Board for Stinson Beach and a longtime resident.

The county and the National Park Service, which owns the parking lot as part of the Golden Gate National Recreation Area, have taken preventive measures to help guide flood waters away from businesses and homes. Some of those measures have held, others have not been drastic enough and yet others exacerbated problems.

In 2013, the Marin County Flood Control and Water Conservation District built a 150-foot long, 35-foot wide basin between the access road to the parking lot and the Parkside to the south that is designed to collect sediment that Easkoot Creek brings down from Mount Tamalpais.

The county continues to repair and clear the basin and, as budget allows, to remove sediment and gravel at other sites along the creek during the dry season, when it is least likely to impact protected fish habitat. Last weekend, the basin was not enough to prevent the swollen creek from jumping its bank.

On the other end of the lot, in 2014, the park service completed a passageway—called an “outfall”—that directed flooding creek waters out of the northern lot and into the ocean, away from nearby homes on Calle del Pinos. The park also constructed a sand berm along the ocean side of the parking lot to deflect tidal waves.

But a year later, the park’s sand berm backfired during a storm, trapping flooded creek waters in the parking lot and forcing personnel to manually knock down a portion of it to allow water to drain to the ocean.

Following the damage, the park service made some tweaks to the initial project in 2015 to solve that problem, bringing the total cost of the project to $180,000. It fortified the outfall with pre-cast concrete blocks and large riprap keyed 18 feet down into the ground.

At the time, the park also reconstructed the sand berm—originally one foot high—to slope downward, and raised the height of a second sand berm between the lot and the homes to two feet.

Those alterations proved effective last weekend, as no homes were impacted.

Other recommended projects have stalled due to a lack of funding.

In 2014, a county study called the Stinson Beach Watershed Program Flood Study and Alternatives Assessment recommended bypassing flood flows to either the north or south parking lots by dredging and restoring wetlands.

Julian Kaelon, the spokesman for the Department of Public Works, explained this week that the county didn’t end up with funding to implement the project.

In response to last weekend’s storm, Mr. Kaelon said the department will likely conduct additional sediment removal this year.

Though more extensive, in-water dredging was once more common along Easkoot Creek, the designation of coho salmon and steelhead trout as endangered and threatened species requires permitting that leads to a lengthier and much more expensive process.

Despite these permitting issues, how to manage the creek’s tendency to jump its banks during large storms remains primarily a question of funding, according to Mr. Washington.

“We know what we should be doing—but we just don’t have the capacity to do it,” he said.

For now, the park service is working with the county to remove the debris from the beach parking lot. A spokeswoman for the recreation area, Erin Heimbinder, said the central lot would reopen first, but she did not have an estimate for when.

The more extensive repairs in the north part of the lot will have to wait, given that the creek is still flowing through it.

In the meantime, residents and business owners are bracing themselves for the impact of losing the town’s largest parking area. Katie Beacock, the owner of Seadrift Realty, reported that on Monday, cars lined Calle del Arroyo, the street that leads to Seadrift, which generally only fills up on summer weekends. (The weather was balmy, however, and it’s spring break for many Marin schools, she noted).

Point Blue ecologist Diana Humple said the rain gauge at the organization’s Palomarin field station recorded a total of 6.65 inches between Thursday evening and Saturday morning. Within a 24-hour period, 4.02 inches were measured, seconding a record from 1982 that saw 6.7 inches in the same time frame.

“I haven’t seen that much water coming off the mountain in many years,” said Ms. Beacock, who drove over Mount Tamalpais into Stinson Beach last Saturday. “Everywhere there were little waterfalls, gorgeous, gushy and oozing.”